Letter by Bishu Regarding Article, “Effect of Pulmonary Hypertension Hemodynamic Presentation on Clinical Outcomes in Patients With Severe Symptomatic Aortic Valve Stenosis Undergoing Transcatheter Aortic Valve Implantation: Insights From the New Proposed Pulmonary Hypertension Classification”

Updated definition of pulmonary hypertension and outcome after transcatheter aortic valve implantation

OBJECTIVE

The European Society of Cardiology guidelines have recently defined new cut-offs for pulmonary hypertension (PH) and pulmonary vasculature resistance (PVR; median pulmonary artery pressure (mPAP) >20 instead of 25 mm Hg and PVR >2 instead of 3 Wood unit). The prognostic value of this updated classification after transcatheter aortic valve implantation (TAVI) is unknown.

METHODS

579 consecutive patients treated by TAVI with preprocedural right heart catheterisation evaluation were included. Patients were grouped as: (1) no PH, (2) isolated precapillary/combined (I-PreC/Co) PH and (3) isolated postcapillary PH (I-PoC). All-cause death, cardiovascular death and hospitalisations for heart failure (HF) were evaluated at follow-up. We also analysed the prognostic role of residual postprocedural PH.

RESULTS

Out of 579 patients, 299 (52%) had PH according to the new criteria compared with 185 (32%) according to the previous ones. Overall median age was 82 years, while 55.3% patients were male. Patients with PH were more frequently diagnosed with chronic obstructive pulmonary disease and atrial fibrillation and were characterised by higher surgical risk as compared with patients without PH.At a median follow-up of 2.9 years, the presence of PH according to previous definition was associated with worse survival (p<0.001) and HF hospitalisation (p=0.002) rates, irrespective of PVR values. With newer cut-offs, PH was associated with worse outcomes only in patients with increased PVR, while no differences were found between patients with PH and normal PVR values and those without PH. Postprocedural mPAP normalisation was observed in 45% of the cases, but it was associated with improved long-term survival only in the I-PoC PH group.

CONCLUSIONS

New ESC PH cut-offs increased the number of PH diagnoses. The presence of PH, particularly in the setting of increased PVR, identify patients at higher risk for postprocedural mortality and rehospitalisation. Normalisation of PH was associated with better survival only in I-PoC group.

Prevalence of pulmonary hypertension in aortic stenosis and its influence on outcomes

OBJECTIVE

The significance of pulmonary hypertension (PHT) complicating aortic stenosis (AS) is poorly characterised. In a large cohort of adults with at least moderate AS, we aimed to describe the prevalence and prognostic importance of PHT in such patients.

METHODS

In this retrospective study, we analysed the National Echocardiography Database of Australia (data from 2000 to 2019). Adults with an estimated right ventricular systolic pressure (eRVSP), left ventricular ejection fraction (LVEF) >50% and with moderate or greater AS were included (n=14 980). These subjects were then categorised according to their eRVSP. The relationship between PHT severity and mortality outcomes were evaluated (median follow-up of 2.6 years, IQR 1.0-4.6 years).

RESULTS

Subjects were aged 77±13 years and 57.4% were female. Overall, 2049 (13.7%), 5085 (33.9%), 4380 (29.3%), 1956 (13.1%) and 1510 (10.1%) patients had no (eRVSP<30.00 mm Hg), borderline (30.00-39.99 mm Hg), mild (40.00-49.99 mm Hg), moderate (50.00-59.99 mm Hg) and severe PHT (>60.00 mm Hg), respectively. An echocardiographic phenotype was evident with worsening PHT, showing rising E:e' ratio and right and left atrial sizes(p<0.0001, for all). Adjusted analyses showed that the risk of long-term mortality progressively rose as eRVSP level increased (HR 1.14-2.94, borderline to severe PHT, p<0.0001 for all). A mortality threshold was identified in the 4th decile of eRVSP categories (35.01-38.00 mm Hg; HR 1.19, 95% CI 1.04 to 1.35), with risk progressively increasing through to the 10th decile (HR 2.86, 95% CI 2.54 to 3.21).

CONCLUSIONS

In this large cohort study, we find that PHT is common in ≥moderate AS and mortality increases as PHT becomes more severe. A threshold for higher mortality lies within the range of 'borderline-mild' PHT.

TRIAL REGISTRATION NUMBER

ACTRN12617001387314.

Futility in Transcatheter Aortic Valve Implantation: A Search for Clarity

Although transcatheter aortic valve implantation (TAVI) has revolutionised the landscape of treatment for aortic stenosis, there exists a cohort of patients where TAVI is deemed futile. Among the pivotal high-risk trials, one-third to half of patients either died or received no symptomatic benefit from the procedure at 1 year. Futility of TAVI results in the unnecessary exposure of risk for patients and inefficient resource utilisation for healthcare services. Several cardiac and extra-cardiac conditions and frailty increase the risk of mortality despite TAVI. Among the survivors, these comorbidities can inhibit improvements in symptoms and quality of life. However, certain conditions are reversible with TAVI (e.g. functional mitral regurgitation), attenuating the risk and improving outcomes. Quantification of disease severity, identification of reversible factors and a systematic evaluation of frailty can substantially improve risk stratification and outcomes. This review examines the contribution of pre-existing comorbidities towards futility in TAVI and suggests a systematic approach to guide patient evaluation.